Spectroscope

ABSTRACT

A spectrometer includes a support having a bottom wall part in which a depression including a concave curved inner surface and a peripheral part adjacent to the depression are provided, and a side wall part disposed on a side on which the depression is open with respect to the bottom wall part, a light detection element supported by the side wall part while opposing the depression, and a dispersive part disposed on the inner surface of the depression. A length of the depression in a second direction in which a plurality of grating grooves included in the dispersive part is aligned is larger than a length of the depression in a third direction orthogonal to the second direction when viewed in a first direction in which the depression and the light detection element oppose each other. An area of the peripheral part adjacent to the depression in the second direction is larger than an area of the peripheral part adjacent to the depression in the third direction when viewed in the first direction.

TECHNICAL FIELD

The present disclosure relates to a spectrometer which disperses anddetects light.

BACKGROUND ART

There has been a known spectrometer including a box-shaped supportprovided with a depression on the inside thereof, a light detectionelement attached to an opening of the support, a resin layer disposed tocover the depression of the support, and a dispersive part provided inthe resin layer (for example, see Patent Literature 1).

CITATION LIST Patent Literature

Patent Literature 1: Japanese Unexamined Patent Publication No.2010-256670

SUMMARY OF INVENTION Technical Problem

The above-described spectrometer requires further miniaturization, inparticular, thinning in response to expansion of use. However, as thespectrometer is further thinned, an influence of stray light relativelyincreases, thereby increasing concern about a decrease in detectionaccuracy of the spectrometer.

It is therefore an object of an aspect of the disclosure to provide aspectrometer which can attempt thinning while suppressing a decrease indetection accuracy.

Solution to Problem

A spectrometer in accordance with one aspect of the disclosure includesa support having a bottom wall part in which a depression including aconcave curved inner surface and a peripheral part adjacent to thedepression are provided, and a side wall part disposed on a side onwhich the depression is open with respect to the bottom wall part, alight detection element supported by the side wall part while opposingthe depression, and a dispersive part disposed on the inner surface ofthe depression, wherein a length of the depression in a second directionin which a plurality of grating grooves included in the dispersive partis aligned is larger than a length of the depression in a thirddirection orthogonal to the second direction when viewed in a firstdirection in which the depression and the light detection element opposeeach other, and an area of the peripheral part adjacent to thedepression in the second direction is larger than an area of theperipheral part adjacent to the depression in the third direction whenviewed in the first direction.

In this spectrometer, the dispersive part is disposed on the innersurface of the depression provided on the bottom wall part of thesupport, and the light detection element is supported by the side wallpart of the support while opposing the depression. According to such aconfiguration, it is possible to reduce the size of the spectrometer. Inparticular, since the length of the depression in the second directionin which the plurality of grating grooves included in the dispersivepart is aligned is larger than the length of the depression in the thirddirection orthogonal to the second direction when viewed in the firstdirection in which the depression and the light detection element opposeeach other, and the area of the peripheral part adjacent to thedepression in the second direction is larger than the area of theperipheral part adjacent to the depression in the third direction, it ispossible to thin the spectrometer in the third direction. In addition,even when light dispersed and reflected by the dispersive part isreflected by the light detection element, the light may be inhibitedfrom becoming stray light by letting the light into the peripheral partadjacent to the depression in the second direction. Therefore, accordingto this spectrometer, it is possible to attempt thinning whilesuppressing a decrease in detection accuracy.

In a spectrometer in accordance with one aspect of the disclosure, theside wall part may have an annular shape enclosing the depression andthe peripheral part when viewed in the first direction. In this way, itis possible to reliably suppress deterioration of a characteristic ofthe dispersive part.

In a spectrometer in accordance with one aspect of the disclosure, theperipheral part may include an inclined surface away from the lightdetection element as the inclined surface is away from the depression.In this way, even when light dispersed and reflected by the dispersivepart is reflected by the light detection element, the light may be morereliably inhibited from becoming stray light by letting the light intothe inclined surface of the peripheral part.

In a spectrometer in accordance with one aspect of the disclosure, thedispersive part may be offset so as to be disposed on one side in thesecond direction with respect to a center of the depression when viewedin the first direction, and an area of the peripheral part located onone side of the depression in the second direction may be larger than anarea of the peripheral part located on the other side of the depressionin the second direction when viewed in the first direction. In this way,even when light dispersed and reflected by the dispersive part isreflected by the light detection element, the light may be more reliablyinhibited from becoming stray light by letting the light into theperipheral part located on the one side of the depression in the seconddirection.

In a spectrometer in accordance with one aspect of the disclosure, aboundary line between the depression and the peripheral part adjacent toeach other in the second direction may traverse the bottom wall partalong the third direction when viewed in the first direction. In thisway, it is possible to increase the quantity of light to be dispersed byincreasing the length of the dispersive part in the third direction,thereby improving detection sensitivity.

In a spectrometer in accordance with one aspect of the disclosure, theinner surface of the depression may be curved in a shape of a curvedsurface in each of the second direction and the third direction. In thisway, it is possible to accurately concentrate the light dispersed by thedispersive part on a predetermined position of the light detectionelement while attempting an increase in the quantity of light to bedispersed.

In a spectrometer in accordance with one aspect of the disclosure, theplurality of grating grooves may be curved in a curved line shape on thesame side when viewed in the first direction. In this way, it ispossible to accurately concentrate the light dispersed by the dispersivepart on a predetermined position of the light detection element.

In a spectrometer in accordance with one aspect of the disclosure,shapes of the depression and the peripheral part may be formed by ashape of the support. In this way, the shapes of the depression and theperipheral part are accurately and stably demarcated, and thus it ispossible to obtain the highly accurate dispersive part.

In a spectrometer in accordance with one aspect of the disclosure, theside wall part may have a pair of first side walls opposing each otherwith the depression and the peripheral part interposed therebetween inthe second direction and a pair of second side walls opposing each otherwith the depression and the peripheral part interposed therebetween inthe third direction when viewed in the first direction. In this way, itis possible to simplify a configuration of the support.

In a spectrometer in accordance with one aspect of the disclosure, innersurfaces of the pair of first side walls opposing each other may beinclined to be away from each other as the inner surfaces are away fromthe depression and the peripheral part and approach the light detectionelement. In this way, it is possible to inhibit stress from acting onthe dispersive part by relatively increasing the thickness of the sidewall part on the side of the depression in which the dispersive part isprovided. In addition, it is possible to reduce the weight of thesupport by relatively decreasing the thickness of the side wall part onthe light detection element side.

In a spectrometer in accordance with one aspect of the disclosure, innersurfaces of the pair of second side walls opposing each other may beinclined to be away from each other as the inner surfaces are away fromthe depression and the peripheral part and approach the light detectionelement. In this way, it is possible to inhibit stress from acting onthe dispersive part by relatively increasing the thickness of the sidewall part on the side of the depression in which the dispersive part isprovided. In addition, it is possible to reduce the weight of thesupport by relatively decreasing the thickness of the side wall part onthe light detection element side.

In a spectrometer in accordance with one aspect of the disclosure, thespectrometer may further include a first reflection part disposed on theinner surface of the depression, wherein a light passing part, a secondreflection part, and a light detection part may be provided in the lightdetection element, the first reflection part may reflect light passingthrough the light passing part, the second reflection part may reflectlight reflected by the first reflection part, the dispersive part maydisperse and reflect light reflected by the second reflection part, andthe light detection part may detect light dispersed and reflected by thedispersive part. Reflecting light passing through the light passing partby the first reflection part and the second reflection part in orderfacilitates adjustment of an incidence direction of the light enteringthe dispersive part and a diffusion or convergence state of the light.Thus, even when an optical path length from the dispersive part to thelight detection part is shortened, the light dispersed by the dispersivepart may be accurately concentrated on a predetermined position of thelight detection part.

A spectrometer in accordance with one aspect of the disclosure includesa support having a bottom wall part and a side wall part disposed on oneside of the bottom wall part, a dispersive part disposed on the one sideof the bottom wall part, a light detection element disposed in a firstwidened part in which a space inside the support is widened on anopposite side from the bottom wall part in the side wall part, a coverdisposed in a second widened part in which a space inside the firstwidened part is widened on the opposite side from the bottom wall partin the side wall part, and a wiring electrically connected to the lightdetection element, the wiring extending to an outer surface of thesupport through the first widened part and the second widened part,wherein a side surface of the first widened part is inclined to form anobtuse angle with a bottom surface of the first widened part, a sidesurface of the second widened part is inclined to form an obtuse anglewith a bottom surface of the second widened part, and a region in whichat least the wiring is disposed on an end surface of the support on anopposite side from the bottom wall part is located on a side of thebottom wall part with respect to a surface of the cover on an oppositeside from the bottom wall part.

In this spectrometer, the side surface of the first widened part isinclined to form an obtuse angle with the bottom surface of the firstwidened part, the side surface of the second widened part is inclined toform an obtuse angle with the bottom surface of the second widened part.In this way, it is possible to easily and accurately draw the wiring. Inaddition, it is possible to reduce stress generated in the wiring.Further, in this spectrometer, the region in which at least the wiringis disposed on the end surface of the support on the opposite side fromthe bottom wall part is located on the side of the bottom wall part withrespect to the surface of the cover on the opposite side from the bottomwall part. In this way, it is possible to prevent the wiring from cominginto contact with another member at the time of mounting thespectrometer. In addition, it is possible to reduce the length of thewiring.

In a spectrometer in accordance with one aspect of the disclosure, oneterminal of the light detection element and one end part of the wiringopposing each other in the first widened part may be connected to eachother by a plurality of bumps, and the plurality of bumps may be alignedalong a direction in which a plurality of grating grooves included inthe dispersive part is aligned. In this way, for example, it is possibleto inhibit a positional relationship between the plurality of gratinggrooves in the dispersive part and the plurality of light detectionchannels in the light detection part of the light detection element fromvarying due to thermal expansion of the support, etc. In addition, it ispossible to sufficiently ensure the area of each terminal bytwo-dimensionally disposing the bumps when compared to a case in whichthe bumps are disposed in one row since there is room in availablespace.

In a spectrometer in accordance with one aspect of the disclosure, thecover and the light detection element may be away from each other. Inthis way, it is possible to more reliably remove stray light by a spacebetween the cover and the light detection element.

In a spectrometer in accordance with one aspect of the disclosure, acoefficient of thermal expansion of the support in the direction inwhich the plurality of grating grooves included in the dispersive partis aligned may be smaller than a coefficient of thermal expansion of thesupport in a direction orthogonal to both the direction in which theplurality of grating grooves is aligned and a direction in which thedispersive part and the light detection element oppose each other. Inthis way, it is possible to inhibit a positional relationship betweenthe plurality of grating grooves in the dispersive part and theplurality of light detection channels in the light detection part of thelight detection element from varying due to thermal expansion of thesupport.

In a spectrometer in accordance with one aspect of the disclosure, amember made of resin may be filled between the side surface of the firstwidened part and the light detection element. In this way, it ispossible to stably support the light detection element.

In a spectrometer in accordance with one aspect of the disclosure, amember made of resin may be filled between the side surface of thesecond widened part and the cover. In this way, it is possible to stablysupport the cover.

Advantageous Effects of Invention

According to an aspect of the disclosure, it is possible to provide aspectrometer which can attempt thinning while suppressing a decrease indetection accuracy.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a spectrometer in accordance with anembodiment of the disclosure.

FIG. 2 is a cross-sectional view taken along II-II line of FIG. 1.

FIG. 3 is a cross-sectional view taken along III-III line of FIG. 1.

FIG. 4 is a cross-sectional view taken along IV-IV line of FIG. 1.

FIGS. 5A and 5B are cross-sectional views illustrating a process of amethod for manufacturing the spectrometer of FIG. 1.

FIGS. 6A and 6B are cross-sectional views illustrating a process of themethod for manufacturing the spectrometer of FIG. 1.

FIGS. 7A and 7B are cross-sectional views illustrating a process of themethod for manufacturing the spectrometer of FIG. 1.

FIGS. 8A and 8B are cross-sectional views illustrating a process of themethod for manufacturing the spectrometer of FIG. 1.

FIGS. 9A and 9B are cross-sectional views illustrating a process of themethod for manufacturing the spectrometer of FIG. 1.

FIGS. 10A and 10B are cross-sectional views illustrating a process ofthe method for manufacturing the spectrometer of FIG. 1.

FIGS. 11A and 11B are cross-sectional views of a modified example of thespectrometer of FIG. 1.

FIGS. 12A and 12B are cross-sectional views of a modified example of thespectrometer of FIG. 1.

FIG. 13 is a cross-sectional view of a modified example of thespectrometer of FIG. 1.

DESCRIPTION OF EMBODIMENTS

In the following, an embodiment of the disclosure will be explained indetail with reference to the drawings. In the drawings, the same orequivalent parts will be referred to with the same signs while omittingtheir overlapping descriptions.

[Configuration of Spectrometer]

As illustrated in FIG. 1, in a spectrometer 1, a box-shaped package 2includes a support 10 and a cover 20. The support 10 is configured as amolded interconnect device (MID) and has a plurality of wirings 11. Forexample, the spectrometer 1 is formed in a shape of a rectangularparallelepiped, a length of which in each of an X-axis direction, aY-axis direction (a direction orthogonal to the X-axis direction), and aZ-axis direction (a direction orthogonal to the X-axis direction and theY-axis direction) is less than or equal to 15 mm. In particular, thespectrometer 1 is thinned to a length of about several mm in the Y-axisdirection.

As illustrated in FIG. 2 and FIG. 3, a light detection element 30, aresin layer 40, and a reflecting layer 50 are provided in the package 2.A first reflection part 51 and a dispersive part 52 are provided in thereflecting layer 50. A light passing part 31, a second reflection part32, a light detection part 33, and a zero-order light capture part 34are provided in the light detection element 30. The light passing part31, the first reflection part 51, the second reflection part 32, thedispersive part 52, the light detection part 33, and the zero-orderlight capture part 34 are aligned on the same straight line parallel tothe X-axis direction when viewed in an optical axis direction of lightL1 (that is, the Z-axis direction) passing through the light passingpart 31.

In the spectrometer 1, the light L1 passing through the light passingpart 31 is reflected by the first reflection part 51, and the light L1reflected by the first reflection part 51 is reflected by the secondreflection part 32. The light L1 reflected by the second reflection part32 is dispersed and reflected by the dispersive part 52. In lightdispersed and reflected by the dispersive part 52, light L2 other thanzero-order light L0 directed to the light detection part 33 enters thelight detection part 33 and is detected by the light detection part 33,and the zero-order light L0 enters the zero-order light capture part 34and is captured by the zero-order light capture part 34. An optical pathof the light L from the light passing part 31 to the dispersive part 52,an optical path of the light L2 from the dispersive part 52 to the lightdetection part 33, and an optical path of the zero-order light L0 fromthe dispersive part 52 to the zero-order light capture part 34 areformed in a space S inside the package 2.

The support 10 has a bottom wall part 12 and a side wall part 13. Adepression 14 and peripheral parts 15 and 16 are provided on a surfaceof the bottom wall part 12 on the space S side. The side wall part 13 isdisposed on a side on which the depression 14 is open with respect tothe bottom wall part 12. The side wall part 13 has a rectangular annularshape that encloses the depression 14 and the peripheral parts 15 and 16when viewed in the Z-axis direction.

More specifically, the side wall part 13 has a pair of first side walls17 and a pair of second side walls 18. The pair of first side walls 17opposes each other with the depression 14 and the peripheral parts 15and 16 interposed therebetween in the X-axis direction when viewed inthe Z-axis direction. The pair of second side walls 18 opposes eachother with the depression 14 and the peripheral parts 15 and 16interposed therebetween in the Y-axis direction when viewed in theZ-axis direction. The bottom wall part 12 and the side wall part 13 areintegrally formed by ceramic such as AlN, Al₂O₃, etc.

A first widened part 13 a and a second widened part 13 b are provided inthe side wall part 13. The first widened part 13 a is a stepped part inwhich the space S is widened only in the X-axis direction on theopposite side from the bottom wall part 12. The second widened part 13 bis a stepped part in which the first widened part 13 a is widened ineach of the X-axis direction and the Y-axis direction on the oppositeside from the bottom wall part 12. A first end part 11 a of each of thewirings 11 is disposed in the first widened part 13 a. Each of thewirings 11 reaches a second end part 11 b disposed on an outer surfaceof one of the second side walls 18 through the second widened part 13 band outer surfaces of the first side walls 17 from the first end part 11a (see FIG. 1). Each second end part 11 b functions as an electrode padfor mounting the spectrometer 1 on an external circuit board, andinputs/outputs an electric signal to/from the light detection part 33 ofthe light detection element 30 through each wiring 11.

As illustrated in FIG. 2, FIG. 3, and FIG. 4, a length of the depression14 in the X-axis direction is larger than a length of the depression 14in the Y-axis direction when viewed in the Z-axis direction. Thedepression 14 includes a concave curved inner surface 14 a. For example,the inner surface 14 a has a shape in which both sides of a sphericalsurface (spherical crown) are cut off by a plane parallel to a ZX plane.In this way, the inner surface 14 a is curved in a shape of a curvedsurface in each of the X-axis direction and the Y-axis direction. Thatis, the inner surface 14 a is curved in a shape of a curved surface whenviewed in the Y-axis direction (see FIG. 2) and when viewed in theX-axis direction (see FIG. 3).

Each of the peripheral parts 15 and 16 is adjacent to the depression 14in the X-axis direction. The peripheral part 15 is located on one firstside wall 17 side (one side in the X-axis direction) with respect to thedepression 14 when viewed in the Z-axis direction. The peripheral part16 is located on the other first side wall 17 side (the other side inthe X-axis direction) with respect to the depression 14 when viewed inthe Z-axis direction. An area of the peripheral part 15 is larger thanan area of the peripheral part 16 when viewed in the Z-axis direction.In the spectrometer 1, the area of the peripheral part 16 is narrowed tothe extent that an outer edge of the inner surface 14 a of thedepression 14 comes into contact with the inner surface 17 a of theother first side wall 17 when viewed in the Z-axis direction. Theperipheral part 15 includes an inclined surface 15 a. The inclinedsurface 15 a is inclined to be away from the light detection element 30along the Z-axis direction as the inclined surface 15 a is away from thedepression 14 along the X-axis direction.

Shapes of the depression 14 and the peripheral parts 15 and 16 areformed by a shape of the support 10. That is, the depression 14 and theperipheral parts 15 and 16 are demarcated only by the support 10. Theinner surface 14 a of the depression 14 and an inner surface 17 a of onefirst side wall 17 are connected to each other through the peripheralpart 15 (that is, physically separated from each other). The innersurface 14 a of the depression 14 and the inner surface 17 a of theother first side wall 17 are connected to each other through theperipheral part 16 (that is, physically separated from each other). Theinner surface 14 a of the depression 14 and an inner surface 18 a ofeach second side wall 18 are connected to each other through anintersecting line (a corner, a bending position, etc.) between a surfaceand a surface. In this way, the inner surface 14 a of the depression 14and the respective inner surfaces 17 a and 18 a of the side wall part 13are connected to each other in a discontinuous state (a physicallyseparated state, a state of being connected to each other through anintersecting line between a surface and a surface. A boundary line 19between the depression 14 and the peripheral part 15 adjacent to eachother in the X-axis direction when viewed in the Z-axis directiontraverses the bottom wall part 12 along the Y-axis direction (see FIG.4). That is, both ends of the boundary line 19 reach the inner surface18 a of each second side wall 18.

As illustrated in FIG. 2 and FIG. 3, the light detection element 30includes a substrate 35. For example, the substrate 35 is formed in arectangular plate shape using a semiconductor material such as silicone.The light passing part 31 is a slit formed in the substrate 35, andextends in the Y-axis direction. The zero-order light capture part 34 isa slit formed in the substrate 35, and is located between the lightpassing part 31 and the light detection part 33 when viewed in theZ-axis direction, and extends in the Y-axis direction. In the lightpassing part 31, an end part on an entrance side of the light L1 widenstoward the entrance side of the light L1 in each of the X-axis directionand the Y-axis directions. In addition, in the zero-order light capturepart 34, an end part on the opposite side from an entrance side of thezero-order light L0 widens toward the opposite side from the entranceside of the zero-order light L0 in each of the X-axis direction and theY-axis directions. When the zero-order light L0 is configured toobliquely enter the zero-order light capture part 34, the zero-orderlight L0 entering the zero-order light capture part 34 may be morereliably inhibited from returning to the space S.

The second reflection part 32 is provided in a region between the lightpassing part 31 and the zero-order light capture part 34 on a surface 35a of the substrate 35 on the space S side. For example, the secondreflection part 32 corresponds to a metal film of Al, Au, etc. andfunctions as a planar mirror.

The light detection part 33 is provided on the surface 35 a of thesubstrate 35. More specifically, the light detection part 33 is put inthe substrate 35 made of the semiconductor material rather than beingattached to the substrate 35. That is, the light detection part 33includes a plurality of photodiodes formed in a first conductivity typeregion inside the substrate 35 made of the semiconductor material and asecond conductivity type region provided within the region. For example,the light detection part 33 is configured as a photodiode array, a C-MOSimage sensor, a CCD image sensor, etc., and has a plurality of lightdetection channels arranged along the X-axis direction. Lights L2 havingdifferent wavelengths are let into the respective light detectionchannels of the light detection part 33. A plurality of terminals 36 forinputting/outputting electric signals to/from the light detection part33 is provided on the surface 35 a of the substrate 35. The lightdetection part 33 may be configured as a surface-incident photodiode ora back surface-incident photodiode. When the light detection part 33 isconfigured as the back surface-incident photodiode, the plurality ofterminals 36 is provided on a surface of the substrate 35 on theopposite side from the surface 35 a. Thus, in this case, each of theterminals 36 is electrically connected to a first end part 11 a of acorresponding wiring 11 by wire bonding.

The light detection element 30 is disposed in the first widened part 13a of the side wall part 13. A terminal 36 of the light detection element30 and the first end part 11 a of the wiring 11 opposing each other inthe first widened part 13 a are connected to each other by a solderlayer 3. For example, the terminal 36 of the light detection element 30and the first end part 11 a of the wiring 11 opposing each other areconnected to each other by the solder layer 3 formed on a surface of theterminal 36 through a plating layer of a base (Ni—Au, Ni—Pd—Au, etc.).In this case, in the spectrometer 1, the light detection element 30 andthe side wall part 13 are fixed to each other by the solder layer 3, andthe light detection part 33 of the light detection element 30 and theplurality of wirings 11 are electrically connected to each other. Forexample, a reinforcing member 7 made of resin is disposed to cover aconnection part between the terminal 36 of the light detection element30 and the first end part 11 a of the wiring 11 opposing each otherbetween the light detection element 30 and the first widened part 13 a.In this way, the light detection element 30 is attached to the side wallpart 13 and supported by the side wall part 13 while opposing thedepression 14. In the spectrometer 1, the Z-axis direction correspondsto a first direction in which the depression 14 and the light detectionelement 30 oppose each other.

The resin layer 40 is disposed on the inner surface 14 a of thedepression 14. The resin layer 40 is formed by pressing a mold dieagainst a resin material corresponding to a molding material (e.g.,photocuring epoxy resins, acrylic resins, fluorine-based resins,silicone, and replica optical resins such as organic/inorganic hybridresins) and curing the resin material (by photocuring using UV light orthermal curing, etc.) in this state.

A grating pattern 41 is provided in a region of the resin layer 40offset so as to be disposed on the peripheral part 15 side (one side inthe X-axis direction) with respect to a center of the depression 14 whenviewed in the Z-axis direction. For example, the grating pattern 41corresponds to a blazed grating having a serrated cross section, abinary grating having a rectangular cross section, a holographic gratinghaving a sinusoidal cross section, etc.

The resin layer 40 is away from the inner surface 17 a of the one firstside wall 17 (the first side wall 17 on the left side in FIG. 2) andcomes into contact with each of the inner surface 17 a of the otherfirst side wall 17 (the first side wall 17 on the right side in FIG. 2),an inner surface 18 a of one second side wall 18, and an inner surface18 a of the other second side wall 18. The resin layer 40 widens alongeach of the inner surface 17 a of the other first side wall 17, theinner surface 18 a of the one second side wall 18, and the inner surface18 a of the other second side wall 18 to climb up the inner surfaces 17a and 18 a from the inner surface 14 a.

A thickness of the resin layer 40 in the Z-axis direction is larger in apart 43 in contact with the inner surface 17 a and a part 44 in contactwith the inner surface 18 a than in a part 42 disposed on the innersurface 14 a. That is, a “thickness H2 along the Z-axis direction” ofthe part 43 in the resin layer 40 in contact with the inner surface 17 aand a “thickness H3 along the Z-axis direction” of the part 44 in theresin layer 40 in contact with the inner surface 18 a are larger than a“thickness H1 along the Z-axis direction” of the part 42 in the resinlayer 40 disposed on the inner surface 14 a. For example, H1 is aboutseveral μ to 80 μm (a minimum value is greater than or equal to athickness enough to fill surface roughness of the support 10), and eachof H2 and H3 is about several hundred μm.

The resin layer 40 reaches the inclined surface 15 a of the peripheralpart 15. The thickness of the resin layer 40 in the Z-axis direction islarger in a part 45 reaching the peripheral part 15 than in the part 42disposed on the inner surface 14 a. That is, a “thickness H4 along theZ-axis direction” of the part 45 in the resin layer 40 reaching theperipheral part 15 is larger than the “thickness H1 along the Z-axisdirection” of the part 42 in the resin layer 40 disposed on the innersurface 14 a. For example, H4 is about several hundred μm.

Here, when the “thicknesses along the Z-axis direction” in therespective parts 42, 43, 44, and 45 change, an average value of thethicknesses in the respective parts 42, 43, 44, and 45 may be regardedas the “thicknesses along the Z-axis direction” of the respective parts42, 43, 44, and 45. A “thickness along a direction orthogonal to theinner surface 17 a” of the part 43 in contact with the inner surface 17a, a “thickness along a direction orthogonal to the inner surface 18 a”of the part 44 in contact with the inner surface 18 a, and a “thicknessalong a direction orthogonal to the inclined surface 15 a” of the part45 reaching the peripheral part 15 are larger than the “thickness H1along a direction orthogonal to the inner surface 14 a” of the part 42disposed on the inner surface 14 a. The resin layer 40 described aboveis formed in a continuous state.

The reflecting layer 50 is disposed on the resin layer 40. For example,the reflecting layer 50 corresponds to a metal film of Al, Au, etc. Aregion of the reflecting layer 50 opposing the light passing part 31 ofthe light detection element 30 in the Z-axis direction corresponds tothe first reflection part 51 functioning as a concave mirror. The firstreflection part 51 is disposed on the inner surface 14 a of thedepression 14, and is offset so as to be disposed on the peripheral part16 side (the other side in the X-axis direction) with respect to thecenter of the depression 14 when viewed in the Z-axis direction. Aregion of the reflecting layer 50 covering the grating pattern 41 of theresin layer 40 corresponds to the dispersive part 52 functioning as areflection grating. The dispersive part 52 is disposed on the innersurface 14 a of the depression 14, and is offset so as to be disposed onthe peripheral part 15 side (the one side in the X-axis direction) withrespect to the center of the depression 14 when viewed in the Z-axisdirection. In this way, the first reflection part 51 and the dispersivepart 52 are provided in the resin layer 40 on the inner surface 14 a ofthe depression 14.

A plurality of grating grooves 52 a included in the dispersive part 52has a shape conforming to a shape of the grating pattern 41. Theplurality of grating grooves 52 a is aligned in the X-axis directionwhen viewed in the Z-axis direction, and is curved in a curved lineshape (for example, an arc shape convex to the peripheral part 15 side)on the same side when viewed in the Z-axis direction (see FIG. 4). Inthe spectrometer 1, the X-axis direction corresponds to a seconddirection in which the plurality of grating grooves 52 a is aligned whenviewed in the Z-axis direction, and the Y-axis direction is a thirddirection orthogonal to the second direction when viewed in the Z-axisdirection.

The reflecting layer 50 covers the whole part 42 (including the gratingpattern 41) disposed on the inner surface 14 a of the depression 14, thewhole part 43 in contact with the inner surface 17 a of the other firstside wall 17, the whole part 44 in contact with the inner surface 18 aof each second side wall 18, and a portion of the part 45 reaching theperipheral part 15 in the resin layer 40. That is, the reflecting layer50 included in the first reflection part 51 and the dispersive part 52is disposed on the resin layer 40 in a continuous state.

The cover 20 has a light transmitting member 21 and a light shieldingfilm 22. For example, the light transmitting member 21 is formed in arectangular plate shape using a material which transmits the light L1therethrough, examples of which include silica, borosilicate glass(BK7), Pyrex (registered trademark) glass, and Kovar glass. The lightshielding film 22 is formed on a surface 21 a of the light transmittingmember 21 on the space S side. A light transmitting opening 22 a isformed in the light shielding film 22 to oppose the light passing part31 of the light detection element 30 in the Z-axis direction. The lighttransmitting opening 22 a is a slit formed in the light shielding film22, and extends in the Y-axis direction.

When an infrared ray is detected, silicon, germanium, etc. is effectiveas a material of the light transmitting member 21. In addition, thelight transmitting member 21 may be provided with an AR (AntiReflection) coat, and may have such a filter function as to transmittherethrough only a predetermined wavelength of light. Further, forexample, a black resist, Al, etc. may be used as a material of the lightshielding film 22. Here, the black resist is effective as the materialof the light shielding film 22 from a viewpoint that the zero-orderlight L0 entering the zero-order light capture part 34 is inhibited fromreturning to the space S. For example, the light shielding film 22 maycorrespond to a composite film including an Al layer covering thesurface 21 a of the light transmitting member 21 and a black resistlayer provided at least in a region of the Al layer opposing thezero-order light capture part 34. That is, in the composite film, the Allayer and the black resist layer are stacked in this order on the spaceS side of the light transmitting member 21.

The cover 20 is disposed in the second widened part 13 b of the sidewall part 13. For example, a sealing member 4 made of resin, solder,etc. is disposed between the cover 20 and the second widened part 13 b.In the spectrometer 1, the cover 20 and the side wall part 13 are fixedto each other by the sealing member 4, and the space S is airtightlysealed.

[Action and Effect]

According to the spectrometer 1, it is possible to attempt thinningwhile suppressing a decrease in detection accuracy for the followingreasons.

First, the dispersive part 52 is disposed on the inner surface 14 a ofthe depression 14 provided in the bottom wall part 12 of the support 10,and the light detection element 30 is supported by the side wall part 13of the support 10 while opposing the depression 14. According to such aconfiguration, it is possible to reduce the size of the spectrometer 1.In particular, in the spectrometer 1, when viewed in the Z-axisdirection, the length of the depression 14 in the X-axis direction islarger than the length of the depression 14 in the Y-axis direction, andthe peripheral part is not provided on the one second side wall 18 sideand the other second side wall 18 side with respect to the depression14. In this way, the spectrometer 1 may be thinned in the Y-axisdirection.

In addition, even when light dispersed and reflected by the dispersivepart 52 is reflected by the light detection element 30, the light may beinhibited from becoming stray light by, for example, letting the lightinto the peripheral part 15 having a sufficient area compared to theperipheral part 16. In particular, in the spectrometer 1, since theperipheral part 15 includes the inclined surface 15 a which is away fromthe light detection element 30 as the inclined surface 15 a is away fromthe depression 14, it is possible to inhibit light reflected by theinclined surface 15 a from directly returning to the light detectionpart 33 of the light detection element 30.

As described above, according to the spectrometer 1, it is possible toattempt thinning while suppressing a decrease in detection accuracy. Inparticular, in the spectrometer 1, the side wall part 13 has an annularshape that encloses the depression 14 and the peripheral parts 15 and 16when viewed in the Z-axis direction. In this way, it is possible toreliably suppress deterioration of a characteristic of the dispersivepart 52. In addition, in the spectrometer 1, the light L1 passingthrough the light passing part 31 is reflected by the first reflectionpart 51 and the second reflection part 32 in order and enters thedispersive part 52, which facilitates adjustment of an incidencedirection of the light L1 entering the dispersive part 52 and adiffusion or convergence state of the light L1. Thus, even when anoptical path length from the dispersive part 52 to the light detectionpart 33 is shortened, the light L2 dispersed by the dispersive part 52may be accurately concentrated on a predetermined position of the lightdetection part 33.

In addition, in the spectrometer 1, the first reflection part 51 and thedispersive part 52 are provided on the depression 14 whose length in theX-axis direction is larger than the length in the Y-axis direction so asto lie along the X-axis direction. In this way, it is possible toimprove detection sensitivity by increasing an effective area of thedispersive part 52 while thinning the spectrometer 1 in the Y-axisdirection. Further, even when light dispersed and reflected by thedispersive part 52 is reflected by the light detection element 30 andreturns to the depression 14, the light may be released to the oppositeside from the light detection part 33.

In addition, in the spectrometer 1, the dispersive part 52 is offset soas to be disposed on one side in the X-axis direction with respect tothe center of the depression 14 when viewed in the Z-axis direction.Further, when viewed in the Z-axis direction, the area of the peripheralpart 15 located on one side of the depression 14 in the X-axis directionis larger than the area of the peripheral part 16 located on the otherside of the depression 14 in the X-axis direction. In this way, evenwhen light dispersed and reflected by the dispersive part 52 isreflected by the light detection element 30, the light may be morereliably inhibited from becoming stray light by letting the light intothe peripheral part 15 located on one side of the depression 14 in theX-axis direction.

In addition, in the spectrometer 1, when viewed in the Z-axis direction,the boundary line 19 between the depression 14 and the peripheral part15 adjacent to each other in the X-axis direction traverses the bottomwall part 12 along the Y-axis direction. In this way, it is possible toincrease the quantity of light to be dispersed by increasing the lengthof the dispersive part 52 in the Y-axis direction, thereby improving thedetection sensitivity.

In addition, in the spectrometer 1, the first reflection part 51 and thedispersive part 52 are disposed on the inner surface 14 a of the onedepression 14. When the first reflection part 51 and the dispersive part52 are provided in separate depressions, respectively, an optical pathis obstructed by a projection formed between the depression and thedepression, so that a degree of freedom of optical path designdecreases. As a result, there is concern that miniaturization of thespectrometer 1 may be hampered. On the other hand, in the spectrometer1, since the first reflection part 51 and the dispersive part 52 areprovided in one depression 14, a degree of freedom of optical pathdesign is improved. As a result, miniaturization of the spectrometer 1is allowed.

In addition, in the spectrometer 1, the inner surface 14 a of thedepression 14 is curved in a shape of a curved surface in each of theX-axis direction and the Y-axis direction. In this way, it is possibleto accurately concentrate the light dispersed by the dispersive part 52on a predetermined position of the light detection element 30 whileattempting an increase in the quantity of light to be dispersed.

In addition, in the spectrometer 1, when viewed in the Z-axis direction,the plurality of grating grooves 52 a is curved in a curved line shapeon the same side. In this way, it is possible to accurately concentratethe light dispersed by the dispersive part 52 on a predeterminedposition of the light detection element 30.

In addition, in the spectrometer 1, the shapes of the depression 14 andthe peripheral parts 15 and 16 are formed by the shape of the support10. In this way, the shapes of the depression 14 and the peripheralparts 15 and 16 are accurately and stably demarcated, and thus it ispossible to obtain the highly accurate dispersive part 52.

In addition, in the spectrometer 1, the first reflection part 51 and thedispersive part 52 are provided in the resin layer 40. In this way, thearea in which the resin layer 40 covers the surface of the support 10increases, and thus it is possible to suppress generation of stray lightcaused by scattering of light on the surface of the support 10. When thesurface of the support 10 is covered with the resin layer 40, it ispossible to easily and accurately obtain a surface capable ofsuppressing scattering of light without being influenced by a state ofthe shape of the support 10.

For example, a material of the support 10 may correspond to ceramic fromviewpoints that it is possible to suppress expansion and contraction ofthe support 10 resulting from a temperature change of an environment inwhich the spectrometer 1 is used, generation of heat in the lightdetection part 33, etc. and it is possible to suppress a decrease indetection accuracy (a shift of peak wavelength in light detected by thelight detection part 33, etc.) resulting from occurrence of a variancein a positional relationship between the dispersive part 52 and thelight detection part 33. In addition, the material of the support 10 maycorrespond to plastic (PPA, PPS, LCP, PEAK, etc.) from a viewpoint thatit is possible to facilitate molding of the support 10 and reduce theweight of the support 10. However, regardless of the material used forthe support 10, the surface roughness of the support 10 is likely to belarge when the support 10 having a certain thickness and size is to beproduced. In particular, when the material of the support 10 correspondsto ceramic, the surface roughness of the support 10 is likely to belarge. In addition, even when the material of the support 10 correspondsto plastic, the surface roughness of the support 10 is likely to berelatively large (for example, about 40 to 50 μm) (in the small-sizedspectrometer 1 in which the depth of the grating groove 52 a is 5 μm orless, the surface roughness of about 40 to 50 μm may be regarded asrelatively large). Therefore, regardless of a material used as thematerial of the support 10, it is possible to easily and accuratelyobtain a surface which is smoother than the surface of the support 10and can suppress scattering of light (the surface of the resin layer 40having smaller surface roughness than the surface roughness of thesupport 10) by covering the surface of the support 10 with the resinlayer 40.

In addition, in the spectrometer 1, the reflecting layer 50 in which thefirst reflection part 51 and the dispersive part 52 are formed isdisposed in a continuous state on the resin layer 40. In this way, thearea in which the reflecting layer 50 covers the surface of the resinlayer 40 increases, and thus it is possible to suppress generation ofstray light resulting from scattering of light on the surface of theresin layer 40. In addition, when light dispersed and reflected by thedispersive part 52 is reflected by the light detection element 30, thelight is reflected by the reflecting layer 50 in the continuous state tothe light passing part 31 side, and thus it is possible to inhibit thelight from directly returning to the light detection part 33. In thiscase, it is difficult to define NA of the light L1 by the firstreflection part 51. However, in the spectrometer 1, it is possible todefine NA of the light L1 entering the space S by the light transmittingopening 22 a of the light shielding film 22 and the light passing part31 of the light detection element 30, and to define NA of the light L1reflected by the first reflection part 51 by the second reflection part32 of the light detection element 30.

In addition, in the spectrometer 1, the support 10 includes the bottomwall part 12 and the side wall part 13, and the side wall part 13includes the pair of first side walls 17 and the pair of second sidewalls 18. In this way, the configuration of the support may besimplified.

In addition, in the spectrometer 1, the zero-order light capture part34, which captures the zero-order light L0 in light dispersed andreflected by the dispersive part 52, is provided in the light detectionelement 30. In this way, it is possible to inhibit the zero-order lightL0 from becoming stray light due to multiple reflections, etc. anddetection accuracy from decreasing.

In addition, in the spectrometer 1, the package 2 includes the support10 and the cover 20, and the space S in the package 2 is airtightlysealed. In this way, it is possible to suppress a decrease in detectionaccuracy resulting from deterioration of a member in the space S due tomoisture, occurrence of condensation in the space S due to a decrease inambient temperature, etc.

[Method for Manufacturing Spectrometer]

A description will be given of a method for manufacturing theabove-described spectrometer 1. First, as illustrated in FIGS. 5A and5B, the support 10 is prepared, and a resin material 5 corresponding toa molding material (for example, photocuring epoxy resins, acrylicresins, fluorine-based resins, silicone, and replica optical resins suchas organic/inorganic hybrid resins) is disposed on the inner surface 14a of the depression 14 (first step).

Subsequently, a mold die 6 is pressed against the resin material 5, andthe resin material 5 is cured (for example, by photocuring using UVlight or thermal curing, etc.) in this state as illustrated in FIGS. 6Aand 6B, thereby forming the resin layer 40 on the inner surface 14 a ofthe depression 14 as illustrated in FIGS. 7A and 7B (second step). Asillustrated in FIGS. 6A and 6B, a molding surface 6 a corresponding tothe inner surface 14 a of the depression 14 is provided on the mold die6, and a pattern 6 b corresponding to the grating pattern 41 is providedon the molding surface 6 a. The molding surface 6 a has smoothness closeto that of a mirror surface.

In this instance, the resin layer 40 having the grating pattern 41 isformed to come into contact with each of the inner surface 17 a of theother first side wall 17, the inner surface 18 a of the one second sidewall 18, and the inner surface 18 a of the other second side wall 18.The resin layer 40 having the grating pattern 41 is formed such that the“thickness H2 along the Z-axis direction” of the part 43 in contact withthe inner surface 17 a and the “thickness H3 along the Z-axis direction”of the part 44 in contact with the inner surface 18 a are larger thanthe “thickness H1 along the Z-axis direction” of the part 42 disposed onthe inner surface 14 a.

When the mold die 6 is pressed against the resin material 5, theperipheral part 15 serves as a shelter for surplus resin. In this way,it is possible to obtain the thin and highly accurate grating pattern41.

Subsequently, as illustrated in FIGS. 8A and 8B, the first reflectionpart 51 and the dispersive part 52 are formed by forming the reflectinglayer 50 on the resin layer 40 (third step). For example, the reflectinglayer 50 is formed by evaporating metal such as Al, Au, etc. Thereflecting layer 50 may be formed by another method other thanevaporation of metal.

Subsequently, as illustrated in FIGS. 9A and 9B, the light detectionelement 30 is disposed in the first widened part 13 a of the side wallpart 13, and the terminal 36 of the light detection element 30 and thefirst end part 11 a of the wiring 11 opposing each other in the firstwidened part 13 a are connected to each other by the solder layer 3.That is, the light detection element 30 is attached to the side wallpart 13 to opposite the depression 14, so that the side wall part 13supports the light detection element 30 (fourth step). In this instance,self-alignment of the light detection element 30 is realized bymelting/re-solidification of the solder layer 3 provided at eachterminal 36. It is possible to realize self-alignment of the lightdetection element 30 by using a solder ball having a core for connectionbetween the terminal 36 of the light detection element 30 and the firstend part 11 a of the wiring 11. Subsequently, for example, thereinforcing member 7 made of resin is disposed to cover the connectionpart between the terminal 36 of the light detection element 30 and thefirst end part 11 a of the wiring 11 opposing each other between thelight detection element 30 and the first widened part 13 a.

Subsequently, as illustrated in FIGS. 10A and 10B, the cover 20 isdisposed in the second widened part 13 b of the side wall part 13, andthe sealing member 4 made of, for example, resin, etc. is disposedbetween the cover 20 and the second widened part 13 b. In this way, thespace S is airtightly sealed, and the spectrometer 1 is obtained.

According to the method for manufacturing the spectrometer 1 describedabove, it is possible to easily manufacture the spectrometer 1 capableof inhibiting the resin layer 40 from being separated from the support10 at the time of releasing the mold die 6, thereby attemptingminiaturization while suppressing a decrease in detection accuracy.

Modified Example

Even though the embodiment of the disclosure has been described above,one aspect of the disclosure is not limited to the above embodiment.

For example, as illustrated in FIGS. 11A and 11B, the inner surfaces 17a of the pair of first side walls 17 opposing each other may be inclinedto be separated from each other as the inner surfaces 17 a are away fromthe depression 14 and the peripheral parts 15 and 16 and approach thelight detection element 30. Similarly, the inner surfaces 18 a of thepair of second side walls 18 opposing each other may be inclined to beseparated from each other as the inner surfaces 18 a are away from thedepression 14 and the peripheral parts 15 and 16 and approach the lightdetection element 30. In this way, it is possible to inhibit stress fromacting on the dispersive part 52 by relatively increasing the thicknessof the side wall part 13 on the side of the depression 14 in which thedispersive part 52 is provided. In addition, it is possible to reducethe weight of the support 10 by relatively decreasing the thickness ofthe side wall part 13 on the light detection element 30 side. Further,the thickness of the resin layer 40 in the part in contact with theinner surface 17 a of the first side wall 17 and the inner surface 18 aof the second side wall 18 may be increased as the resin layer 40 isaway from the depression 14 and the peripheral parts 15 and 16 andapproaches the light detection element 30. When the thickness of theresin layer 40 in the part is made relatively small on the side of thedepression 14 and the peripheral parts 15 and 16 and relatively large onthe side of the light detection element 30, it is possible to inhibitthe resin layer 40 from being separated from the support 10 whileinhibiting stress from acting on the dispersive part 52. In addition, itis possible to easily release the mold die 6 at the time ofmanufacturing the spectrometer 1.

In addition, as illustrated in FIGS. 12A and 12B, the cover 20 and thelight detection element 30 may be joined to each other. In this case,the cover 20 and the light detection element 30 are mounted with respectto the support 10 as follows. In more detail, the cover 20 and the lightdetection element 30 are disposed in the first widened part 13 a of theside wall part 13, and the terminal 36 of the light detection element 30and the first end part 11 a of the wiring 11 opposing each other in thefirst widened part 13 a are connected to each other by the solder layer3. Subsequently, the sealing member 4 made of resin is disposed betweenthe cover 20 and the light detection element 30 and the first widenedpart 13 a. In this way, when the cover 20 and the light detectionelement 30 are joined to each other in advance, it is possible tofacilitate mounting of the cover 20 and the light detection element 30with respect to the support 10. For example, the cover 20 and the lightdetection element 30 are prepared by being joined to each other in astate in which one of the cover 20 and the light detection element 30 isat a wafer level and then performing dicing.

In addition, for example, the terminal 36 of the light detection element30 and the first end part 11 a of the wiring 11 opposing each other maybe connected to each other by a bump made of Au, solder, etc. or aconductive resin such as silver paste. In this case, for example, thereinforcing member 7 made of resin may be disposed to cover theconnection part between the terminal 36 of the light detection element30 and the first end part 11 a of the wiring 11 opposing each otherbetween the light detection element 30 and the first widened part 13 a.

In addition, the light detection element 30 may be indirectly (forexample, through another member such as a glass substrate, etc.)attached to the side wall part 13 as long as the light detection element30 is supported by the side wall part 13.

In addition, the second end part 11 b serving as the electrode pad formounting the spectrometer 1 on the external circuit board may bedisposed in a region other than the outer surface of the one second sidewall 18 as long as the region corresponds to the outer surface of thesupport 10. In either case, the second end part 11 b may be directlymounted on the surface of the external circuit board using a bump,solder, etc.

In addition, without the spectrometer 1 including the first reflectionpart 51 and the second reflection part 32, the light L1 passing throughthe light passing part 31 may be dispersed and reflected by thedispersive part 52, and the light L2 dispersed and reflected by thedispersive part 52 may be incident on the light detection part 33 anddetected by the light detection part 33.

In addition, the inner surfaces 17 a and 18 a of the side wall part 13may not correspond to flat surfaces and may correspond to curvedsurfaces. In addition, for example, the inner surface 14 a of thedepression 14 and the inner surfaces 17 a and 18 a of the side wall part13 may be connected in a continuous state, for example, connectedthrough an R-chamfered surface.

In addition, in the spectrometer 1, when a requirement “when viewed inthe Z-axis direction, the area of the peripheral parts 15 and 16adjacent to the depression 14 in the X-axis direction is larger than thearea of the peripheral parts adjacent to the depression 14 in the Y-axisdirection” is satisfied, the peripheral parts adjacent to the depression14 in the Y-axis direction may be provided in the bottom wall part 12.In this case, the spectrometer 1 may be thinned in the Y-axis direction.The “area of the peripheral part located on the other first side wall 17side with respect to the depression 14”, the “area of the peripheralpart located on the one second side wall 18 side with respect to thedepression 14”, and the “area of the peripheral part located on theother second side wall 18 side with respect to the depression 14”include the case of “0”.

In addition, the inner surface 14 a of the depression 14 may not becurved in a shape of a curved surface in each of the X-axis directionand the Y-axis direction and may be curved in a shape of a curvedsurface in one of the X-axis direction and the Y-axis direction.

In addition, as illustrated in FIG. 13, in the first widened part (firststepped part) 13 a in which the light detection element 30 is disposed,a side surface 13 a ₂ of the first widened part 13 a may be inclined toform an obtuse angle with a bottom surface 13 a ₁ of the first widenedpart 13 a. In addition, in the second widened part (second stepped part)13 b in which the cover 20 is disposed, a side surface 13 b ₂ of thesecond widened part 13 b may be inclined to form an obtuse angle with abottom surface 13 b ₁ of the second widened part 13 b. In this way, itis possible to easily and accurately draw the wiring 11. In addition, itis possible to reduce stress generated in the wiring 11.

In addition, the reinforcing member 7 made of resin may be filledbetween the side surface 13 a ₂ of the first widened part 13 a and thelight detection element 30. In this way, since the reinforcing member 7easily enters a gap when the side surface 13 a ₂ is inclined, it ispossible to more sufficiently reinforce support of the light detectionelement 30 and to more sufficiently ensure airtightness in the part. Inaddition, a shift in position of the light detection element 30 in theX-axis direction (the second direction in which the plurality of gratinggrooves 52 a included in the dispersive part 52 is aligned) may be morereliably suppressed by a synergistic effect with arrangement of a bump16 to be described later. In addition, the sealing member 4 made ofresin may be filled between the side surface 13 b ₂ of the secondwidened part 13 b and the cover 20. In this way, since the sealingmember 4 easily enters a gap when the side surface 13 b ₂ is inclined,it is possible to more sufficiently reinforce support of the cover 20and to more sufficiently ensure airtightness in the part. Theairtightness may be ensured by filling the reinforcing member 7 made ofresin between the side surface 13 a ₂ of the first widened part 13 a andthe light detection element 30, by filling the sealing member 4 made ofresin between the side surface 13 b ₂ of the second widened part 13 band the cover 20, or by filling the reinforcing member 7 between theside surface 13 a ₂ and the light detection element 30 and filling thesealing member 4 between the side surface 13 b ₂ and the cover 20. Theairtightness may be ensured by a configuration (the spectrometer 1 isaccommodated in another package and the inside of the package isairtightly sealed) other than these configurations related to theairtightness.

In addition, as illustrated in FIG. 13, a region 10 a 1 in which atleast the wiring 11 is disposed on an end surface 10 a on the oppositeside from the bottom wall part 12 in the support 10 may be located onthe bottom wall part 12 side with respect to a surface 20 a on theopposite side from the bottom wall part 12 in the cover 20. In this way,it is possible to prevent the wiring 11 from coming into contact withanother member at the time of mounting the spectrometer 1. In addition,it is possible to reduce the length of the wiring 11. The whole endsurface 10 a of the support 10 may be located on the bottom wall part 12side with respect to the surface 20 a of the cover 20.

In addition, as illustrated in FIG. 13, the cover 20 and the lightdetection element 30 may be spaced apart from each other. In this way,stray light may be confined in a space between the cover 20 and thelight detection element 30, and the stray light may be more reliablyremoved.

In addition, a coefficient of thermal expansion of the support 10 in theX-axis direction (the second direction in which the plurality of gratinggrooves 52 a included in the dispersive part 52 is aligned) is less thanor equal to a coefficient of thermal expansion of the support 10 in theY-axis direction (a third direction orthogonal to the first direction inwhich the depression 14 and the light detection element 30 oppose eachother and orthogonal to the second direction) (more preferably, thecoefficient of thermal expansion of the support 10 in the X-axisdirection is smaller than the coefficient of thermal expansion of thesupport 10 in the Y-axis direction). That is, when the coefficient ofthermal expansion of the support 10 in the X-axis direction is set to α,and the coefficient of thermal expansion of the support 10 in the Y-axisdirection is set to β, a relationship of α≤β is satisfied (morepreferably, a relationship of α<β is satisfied). In this way, it ispossible to inhibit a positional relationship between the plurality ofgrating grooves 52 a in the dispersive part 52 and the plurality oflight detection channels in the light detection part 33 of the lightdetection element 30 from varying due to thermal expansion of thesupport 10.

In addition, as illustrated in FIG. 13, for example, one terminal 36 ofthe light detection element 30 and one first end part 11 a of the wiring11 opposing each other may be connected to each other by a plurality ofbumps 61 made of Au, solder, etc., and the plurality of bumps 61 may bealigned along the X-axis direction (the second direction in which theplurality of grating grooves 52 a included in the dispersive part 52 isaligned). Further, a plurality of sets of such one terminal 36, onefirst end part 11 a, and a plurality of bumps 61 may be provided in theY-axis direction. In this way, for example, it is possible to inhibit apositional relationship between the plurality of grating grooves 52 a inthe dispersive part 52 and the plurality of light detection channels inthe light detection part 33 of the light detection element 30 fromvarying due to thermal expansion of the support 10. In addition, it ispossible to sufficiently ensure the area of each terminal 36 bytwo-dimensionally disposing the bumps 61 when compared to a case inwhich the bumps 61 are disposed in one row since there is room inavailable space.

In addition, the first widened part 13 a may correspond to a steppedpart in which the space S (the space in which the optical path of thelight L1 from the light passing part 31 to the dispersive part 52, theoptical path of the light L2 from the dispersive part 52 to the lightdetection part 33, and the optical path of the zero-order light L0 fromthe dispersive part 52 to the zero-order light capture part 34 areformed) is widened at least in one direction (for example, the X-axisdirection) on the opposite side from the bottom wall part 12. The firstwidened part 13 a may include one step or a plurality of steps.Similarly, the second widened part 13 b may correspond to a stepped partin which the first widened part 13 a is widened at least in onedirection (for example, the X-axis direction) on the opposite side fromthe bottom wall part 12. The second widened part 13 b may include onestep or a plurality of steps. In a case in which the light detectionpart 33 is configured as a back surface-incident photodiode, and theplurality of terminals 36 is provided on the surface of the substrate 35on the opposite side from the surface 35 a, when each terminal 36 iselectrically connected to the first end part 11 a of the correspondingwiring 11 by wire bonding, the first end part 11 a of each wiring 11 maybe disposed in a different step (a step on the outer and upper side of astep in which the light detection element 30 is disposed) from the stepin which the light detection element 30 is disposed in the first widenedpart 13 a including the plurality of steps.

In addition, the material of the support 10 is not limited to ceramic,and may correspond to another molding material such as a resin, forexample, LCP, PPA, epoxy, etc. or molding glass. Further, the shape ofthe support 10 is not limited to the shape of the rectangularparallelepiped, and may correspond to, for example, a shape in which acurved surface is provided on the outer surface. Furthermore, the shapeof the side wall part 13 is not limited to the rectangular annular shapeas long as the shape corresponds to an annular shape that encloses thedepression 14 when viewed in the Z-axis direction, and may correspond toa circular annular shape. In this way, a material and a shape of eachcomponent of the spectrometer 1 are not limited to the above-describedmaterial and shape, and it is possible to apply various materials andshapes.

REFERENCE SIGNS LIST

-   -   1 . . . spectrometer, 10 . . . support, 12 . . . bottom wall        part, 13 . . . side wall part, 14 depression, 14 a . . . inner        surface, 15, 16 . . . peripheral part, 15 a . . . inclined        surface, 17 . . . first side wall, 17 a . . . inner surface, 18        . . . second side wall, 18 a . . . inner surface, 19 . . .        boundary line, 30 . . . light detection element, 31 . . . light        passing part, 32 . . . second reflection part, 33 . . . light        detection part, 51 . . . first reflection part, 52 . . .        dispersive part, 52 a . . . grating groove.

The invention claimed is:
 1. A spectrometer comprising: a support havinga bottom wall part, a side wall part disposed on a side with respect tothe bottom wall part, and a cover disposed to the side wall part; acircuit board on which the support is directly mounted; a dispersivepart; a light passing part, and a light detection element having a lightpassing part and a light detection part, and supported by the support,wherein a length of the support in a second direction in which the lightpassing part and the light detection part are aligned is larger than alength of the support in a third direction orthogonal to a firstdirection and the second direction when viewed in the first direction inwhich the bottom wall part and the cover oppose each other, the sidewall part has a pair of first side walls opposing each other in thesecond direction and a pair of second side walls opposing each other inthe third direction when viewed in the first direction, and the lengthof the support in each of the first direction, the second direction andthe third direction is less than or equal to 15 mm.
 2. The spectrometeraccording to claim 1, wherein a thickness of each of the pair of firstside walls is larger than a thickness of each of the pair of second sidewalls.
 3. The spectrometer according to claim 2, wherein a coefficientof thermal expansion of the support in the second direction is smallerthan a coefficient of thermal expansion of the support in the thirddirection.
 4. The spectrometer according to claim 1, wherein the sidewall part has an annular shape enclosing the dispersive part when viewedin the first direction.
 5. The spectrometer according to claim 1,wherein a coefficient of thermal expansion of the support in the seconddirection is smaller than a coefficient of thermal expansion of thesupport in the third direction.
 6. The spectrometer according to claim1, wherein the light detection element is disposed in a first widenedpart in which a space inside the support is widened on an opposite sidefrom the bottom wall part in the side wall part, and the first widenedpart is provided with an end part of a wiring electrically connected tothe light detection element.
 7. The spectrometer according to claim 6,wherein one terminal of the light detection element and the one end partof the wiring opposing each other in the first widened part areconnected to each other by a plurality of bumps, and the plurality ofbumps is aligned along the second direction.
 8. The spectrometeraccording to claim 7, wherein a member made of resin is filled betweenthe side surface of the first widened part and the light detectionelement.
 9. The spectrometer according to claim 6, wherein a member madeof resin is filled between the side surface of the first widened partand the light detection element.
 10. The spectrometer according to claim6, wherein the cover is disposed in a second widened part in which aspace inside the first widened part is widened on the opposite side fromthe bottom wall part in the side wall part.
 11. The spectrometeraccording to claim 10, wherein the cover and the light detection elementare away from each other.
 12. The spectrometer according to claim 11,wherein a member made of resin is filled between the side surface of thesecond widened part and the cover.
 13. The spectrometer according toclaim 10 wherein a member made of resin is filled between the sidesurface of the second widened part and the cover.
 14. The spectrometeraccording to claim 1, wherein the length of the support in the seconddirection is larger than the length of the support in the firstdirection.
 15. The spectrometer according to claim 1, wherein the lightdetection element is indirectly attached to the side wall part throughthe cover.
 16. The spectrometer according to claim 1, wherein a concavecurved surface is provided on a surface of the bottom wall part on thecover side.
 17. The spectrometer according to claim 16, wherein anoptical function part is provided on the concave curved surface.
 18. Thespectrometer according to claim 17, wherein the optical function part isoffset so as to be disposed on a one side in the second direction withrespect to the center of the concave curved surface when viewed in thefirst direction.
 19. The spectrometer according to claim 16, wherein aplurality of optical function parts is provided on the concave curvedsurface.
 20. The spectrometer according to claim 1, wherein the lightdetection element is provided on a semiconductor substrate, and thesemiconductor substrate is smaller than the cover when viewed in thefirst direction.
 21. The spectrometer according to claim 1, wherein anincident light diffuses at the light passing part, and the lightdispersed by the dispersive part converges at the same height as thelight passing part in the first direction.
 22. A spectrometercomprising: a support having a bottom wall part, a side wall partdisposed on a side with respect to the bottom wall part, and a coverdisposed to the side wall part; a circuit board on which the support isdirectly mounted; a dispersive part; a light passing part, and a lightdetection element having a light detection part, and supported by thesupport, wherein a length of the support in a second direction in whichthe light passing part and the light detection part are aligned islarger than a length of the support in a third direction orthogonal to afirst direction and the second direction when viewed in the firstdirection in which the bottom wall part and the cover oppose each other,the side wall part has a pair of first side walls opposing each other inthe second direction and a pair of second side walls opposing each otherin the third direction when viewed in the first direction, and thelength of the support in each of the first direction, the seconddirection and the third direction is less than or equal to 15 mm. 23.The spectrometer according to claim 22, wherein a thickness of each ofthe pair of first side walls is larger than a thickness of each of thepair of second side walls.
 24. The spectrometer according to claim 23,wherein a coefficient of thermal expansion of the support in the seconddirection is smaller than a coefficient of thermal expansion of thesupport in the third direction.
 25. The spectrometer according to claim22, wherein the side wall part has an annular shape enclosing thedispersive part when viewed in the first direction.
 26. The spectrometeraccording to claim 22, wherein a coefficient of thermal expansion of thesupport in the second direction is smaller than a coefficient of thermalexpansion of the support in the third direction.
 27. The spectrometeraccording to claim 22, wherein the light detection element is disposedin a first widened part in which a space inside the support is widenedon an opposite side from the bottom wall part in the side wall part, andthe first widened part is provided with an end part of a wiringelectrically connected to the light detection element.
 28. Thespectrometer according to claim 27, wherein one terminal of the lightdetection element and the one end part of the wiring opposing each otherin the first widened part are connected to each other by a plurality ofbumps, and the plurality of bumps is aligned along the second direction.29. The spectrometer according to claim 28, wherein a member made ofresin is filled between the side surface of the first widened part andthe light detection element.
 30. The spectrometer according to claim 27,wherein a member made of resin is filled between the side surface of thefirst widened part and the light detection element.
 31. The spectrometeraccording to claim 27, wherein the cover is disposed in a second widenedpart in which a space inside the first widened part is widened on theopposite side from the bottom wall part in the side wall part.
 32. Thespectrometer according to claim 31, wherein the cover and the lightdetection element are away from each other.
 33. The spectrometeraccording to claim 32, wherein a member made of resin is filled betweenthe side surface of the second widened part and the cover.
 34. Thespectrometer according to claim 31 wherein a member made of resin isfilled between the side surface of the second widened part and thecover.
 35. The spectrometer according to claim 22, wherein the length ofthe support in the second direction is larger than the length of thesupport in the first direction.
 36. The spectrometer according to claim22, wherein the light detection element is indirectly attached to theside wall part through the cover.
 37. The spectrometer according toclaim 22, wherein a concave curved surface is provided on a surface ofthe bottom wall part on the cover side.
 38. The spectrometer accordingto claim 37, wherein an optical function part is provided on the concavecurved surface.
 39. The spectrometer according to claim 38, wherein theoptical function part is offset so as to be disposed on a one side inthe second direction with respect to the center of the concave curvedsurface when viewed in the first direction.
 40. The spectrometeraccording to claim 37, wherein a plurality of optical function parts isprovided on the concave curved surface.
 41. The spectrometer accordingto claim 22, wherein the light detection element is provided on asemiconductor substrate, and the semiconductor substrate is smaller thanthe cover when viewed in the first direction.
 42. The spectrometeraccording to claim 22, wherein an incident light diffuses at the lightpassing part, and the light dispersed by the dispersive part convergesat the same height as the light passing part in the first direction.